Episode Title:The Magic School Bus Inside Ralphie.Episode Description:It's broadcast day and the class needs Ralphie. The trouble is that he's sick, so his mother, a doctor, won't let him go to school. When Ms. Frizzle says that there is an amazing battle going on inside him, the class decides broadcast day should be about whatever is making Ralphie sick. After shrinking to find out what's going on inside Ralphie, the white blood cells sees the bus as a threat and attempt to devour it.